1. Field of the Invention
Embodiments of the present invention generally relate to the fabrication of integrated circuits. More particularly, the embodiments relates to methods for cleaning carbon containing deposits from a substrate processing chamber.
2. Description of the Related Art
Pre-clean chambers are used in the semiconductor processing industry to remove oxide layers from surfaces of substrates which are to be exposed to layer deposition processes such as chemical vapor deposition. However, during such pre-cleaning processes, carbon containing compounds may escape the substrate and deposit as a film on components of a pre-cleaning chamber. Dielectric domes, such as glass domes, are used in some pre-clean chambers, and may need to be removed for cleaning of carbon deposits. Components that frequently have to be removed are generally provided in a process kit. System operators periodically replace the process kit during routine maintenance for cleaning or disposal. Components of the process kit that are adequately cleaned can be reinstated later.
As the film forms on the process kit surfaces, its density may change, resulting in stress on the film. This stress, along with differences in the coefficients of expansion of the materials in the film and the process kit surfaces, can result in delamination, or flaking, of the film from the surface of the process kit and contamination of the substrate being processed. Because these particles can seriously damage the substrates and/or cause defects to form on the substrates, the process kit is typically replaced after a conservative number of substrates have been cleaned in the system. However, replacement of the process kit is time consuming and reduces throughput of the system even if expensive components can be adequately cleaned outside the chamber.
Therefore, there exists a need to remove in situ the carbon containing film from components of the process kit, such as the dielectric dome, without having to remove the processing kit.